Continuous recorder for color changes



Aug- 31, 1943. R. H. K11-:NLE ETAL 2,328,461

CONTINUOUS RECORDER FOR COLOR CHANGES Original Filed Aug. 29, 1940 4Sheets-Sheet 1 *www Y if Y INVENTORS For H. /r/-AM Aug 31, 1943 R. H.KIENLE Erm. 2,328,461

CONTINUOUS RECORDER ROR COLOR CHANGES original Filed Aug. 29, 1940 4'Smets-sheet 2 i? //0 1f. A if P Il M ATTORNEY.

Aug. 31, 1943. R. H. KIENLE ETAL 2,328,461

CONTINUOUS RECORDER RoR coLoR CHANGES Original Filed Aug. 29, 1940 4Sheets-Sheet 3 START R. H. KIENLE. ETAL CONTINUOUS RECORDER FOR COLORCHANGES Aug. 31, 1943.

Original Filed Aug. 29, 1940 4 Sheets-Sheet 4 INVENTORS Por H. /r/fAu EPag-Pr H. ,P4/Pfr, BY CHA/n rs H, f/vs/Po off Patented Aug. 31, 1943 O FFICE CONTINUOUS RECORDER FOR COLOR CHANGES Roy Herman Kicnle, BoundBrook, Robert H. Park. Bridgewater Township, Somerset County, Charles H.Benbrook, North Plainfield, and Everett F. Grieb, Plainfield, N. J.,assignors to American Cyanamid Company,

New York,

N. Y., a corporation of Maine Original application August 29, 1940,'Serial No.

Divi-ded and this application August 14, 1941, Serial No. 407,412

3 Claims.

This invention relates to devices for continuously recording changes incolor in a reaction and more particularly to continuously record dyeingprocesses.

Many reactions are accompanied by a change in color among which dyeingprocedures are perhaps the most common. It is important to determine howfar a reaction has gone and in case of investigations on new or modifiedreactions, it is also important to follow the course of the reaction.Attempts to do this visually are not in the main satisfactory because noquantitative results are obtained due to the lack of analytical power ofthe eye. In the past, therefore, it has become increasingly the practiceto examine samples of reaction mixtures in which a color change istaking place by putting the sample in a spectrophotometer, colorimeter,or other device capable of giving a measurement of color intensityeither throughout the spectrum or at a given wave length. Suchprocedures, however, require the taking of a sample, putting the samplein the spectrophotometer or colorimeter, obtaining a reading and thentaking another sample. The labor is very great if a large number ofsamples have to be taken and where changes are rapid as they are in somepoints in the reaction, the readings may occur at too long intervals togive a useful indication of color change. Many reactions also suler fromexposure to air which almost invariably occurs in sampling, viz., theleuco of a vat dye.

The present invention is dircted to a device and method for continuousmeasurement of color changes in any system where a colored component isavailable in fluid form. Essentially the present invention includes theco-mbination with the reaction chamber ci" a device for continuouslycirculating a small but representative portion of a colored liquidcomponent through a suitable cell where the transmission at a xed coloris continuously measured. 'I'he measurement is effected by a colorimeterof the photoelectric comparison type. In every case the rate of responseof the system must be sufliciently rapid to insure readings which willgive a correct picture of the change of color with time.

Where indications of changes in transmission at a definite wave lengthare desired and the device is used in conjunction with large scale orlong continued operation with materials where the wave length ofabsorption does not change, the device may be permanently arranged, forexample, a dye vat may be equipped with the present invention includinga suitable colorimeter.

yan actual reaction of the dye with the material being dyed. In othercases the association may be physical. The result, however, is a changein total chemical composition of the bath so that there is a continuouschemical change which is manifested by changes in color, precisely as isthe case in a reaction where there is an actual chemical change takingplace by reacting one component with another. The optical measurement isof course, not concerned with the past history of the color change andthe utility of the present invention is likewise not concerned with theunderlying chemistry which produces the change in color. For this reasonthe terms reaction and reaction mixture in the specication and claimsare used in a somewhat loose form to indicate a change in total chemicalcomposition whether this results from a true chemical reaction or from aphysical removal or addition of certain colored constituents.

While the optical instrument or rather the general type or principles ofoperation of the instruments form an integral part of the inventionsince they determine the nature of the measurement, the presentinvention is not concerned with details of construction of the opticalinstruments except insofar as these constructional details adapt themfor measurement of the circulating liquids which are a feature of thepresent invention. In other words, the present invention is concernedwith a combination of certain types of optical instruments operating oncertain principles with other elements of the finished device or methodand is not concerned with improvements in structural details such aslenses, light sources, and the like. It is an advantage of the presentinvention that standard parts may to a large extent be used in theoptical portion of the apparatus so that it is not necessary to obtainspecial optics with correspondingly increased price. It is also possibleto take standard optical instruments and with only minor structuralchanges incorporate them in the present invention which permits theutilization of suitable colorimeters which are already owned, or permitsobtaining the optical parts of the apparatus in standard form. This isan important advantage as there are few concerns equipped to design andbuild complicated optical apparatus and the possibility of utilizingother types of equipment makes the present invention more generallyavailable.

The present invention is useful not only in the visible portion'of thespectrum but throughout the whole zone of optical radiation, that is tosay, radiations that are capable of being concentrated by optical meansand hence includes infrared and ultraviolet. The internal constructionsof a colorimeter for ultraviolet or infrared frequently have to bemodified because of the nature of the radiation. However, the principlesof the present invention apply in the same way, the only changes beingin the colorimeter portion` of the device and the cell; As the presentinvention has a particular use with measurements made in the visiblespectrum, the specific description which follows will in the main bedirected to this modification.

The invention will be described in greater detail in conjunction withthe drawings in which:

Fig. l is an elevation partly in section and partly broken away of onemodification of the present invention;

Fig. 2 is a detailed elevation partly brokenI away on a larger scale ofthe circulating device of Fig. 1;

Fig. 3 is a diagrammatic section of a device according to Fig. 1inserted in a colorimetric circuit;

Fig. 4 is an enlarged diagrammatic illustration of the recordinggalvanometer of Fig. 3;

Fig. 5 is a typical record obtainable in the colorimeters of Figs. 1 and4;

Fig. 6 is an elevation partly broken away of a somewhat modie...circulating system according to the present iz Jention.

In the figures the same reference numerals will be used to designate thesame functiona parts.

The circulating device shown in Figs. 1, 2, and 3 consists of a reactionchamber I containing a reaction mixture mounted in a wooden framework 2,heating coil 3 connected to a heating relay 21 (Fig. 3) by wires 14 and15, skein holder 4 given up and down oscillatory movements by a shaft 5driven from any suitable source of power (not shown). The liquid fromthe reaction chamber flows downwardly into the thin transmission cell 5,thence into U tube 1, the left hand leg of which is provided with athermometer 8 in a. suitable well (not shown), and the enlarged righthand leg being provided with a mercury U tube I5. The U tube alsocontains toluene on top of the mercury because of its higher coefficientof expansion. An air lift consisting of gas passing through the pipe 9with restricted opening circulates liquid from the right hand leg of theU tube up to the pipe I0, and back into the reaction chamber. The rateof circulation is determined by the amount of gas introduced in the airlift and can be adjusted to suit particular conditions.

The apparatus may be filled through a suitable ller II connected to thetube l0 through the stop cock I2 and the apparatus can be drainedthrough stop cock 32 at the bottom of the U tube. The temperature can bemaintained constant by means of a mercury U tube I5 in which the righthand column of mercury I6 is connected at the bottom to wire 20 and atthe top approaches an electrode I1 which is adjustable by the narrowthreaded shaft I3 and leads to a wire I9 which, with Wire 2U, connect torelay 21 which takes power from the main power line 33 and connects tothe heating coil 3 through the wires 14 and 15. The relay 21 is ofconventional design, its structure having no bearing on the presentinvention. The relay controis in convenient manner the electricalcurrent reaching coil 3 and thus maintains the temperature constant atany predetermined tlgure. In order to heat the apparatus to any desiredoperating temperature the stop cock I4 is opened whereupon the mercuryin the fine tube I4 drops to essentially the same level as that in cupI3, and during the subsequent heating, rises only slightly because themajor part of the mercury which is expelled from. tube I5 by theexpansion of the liquids (toluene and mercury) therein, enters cup I3because of its greater cross sectional area as compared with that oftube I3. When the desired operating temperature has been almost reached,the stop cock i4 is closed whereupon. all subsequent expansion oi theliquids forces mercury into the fine tube I6 until the mercury columntherein touches -the electrode I1 whereupon thecurrent to coil 3 isturned off by the relay 21 and cooling of the system occurs until theconnection with electrode I1 is broken by contraction of the liquids inthe tube I5. The relay 21 then reconnects the current to coil 3 throughthe wires 14 and 15. Thus, the temperature iluctuates over only a verynarrow range. The final setting at the desired temperais accomplished byraising or lowering the metal shaft I8 to which is attached theelectrode I1.

In operation, cell 6 is placed in optical alignment in a comparisoncolorimeter which is shown diagrammatically in Fig-3. The drawings are lpurely diagrammatic and in practice, of course,

the optical system contains suitable'light tight chambers. A projectionlamp 34 is fed from a storage battery 35 or other source of constantvoltage. The beams pass out from the filament of this lamp onto a pairof condensing lenses 36. The transmission cell 6 of Fig. 1 is interposedin one of these beams. This cell is relatively thin, providing a verythin iilm of circulating liquid, for example, the plates forming the twosides of the cell-may be about 0.3 cm. apart. The beam passingthroughthe cell 6 and lens 33 is further condensed by means of lens 38 andpasses through a filter 40 to phototube 42. The other beam passesthrough a similar iilter 39, diaphragm 31 to another phototube 4l. Thediaphragm 31 serves for adjustment of one of the beams so that thegalvanometer reading from the phototube 4I corresponds to that from 42when a medium of complete transparency flows through cell 6. The filtersmay be advantageously double as shown. While the present 'invention doesnot require critical matching of the two iilters as adjustment over areasonably wide range is possible by means of the diaphragm 31, it isdesirable to use iilters 39 and 4B which match closelyas the apparatuswill then read with greater accuracy and adjustment is simpler. Thenlters can, of course, be rapidly changed to obtain measurements at anydesired color.

Phototube 4I is connected by wires 43 and 44 to one set of contacts 45and 43 of a double throw switch, while phototube 42 is connected bywires 41 and 43 to the other set of contacts 49 and 50 of the sameswitch. The center contacts 5I and 52 are in series with a suitablesource of direct current voltage 53, shown diagrammatically as abattery, and a recording galvanometer 54, the details of which are shownin Fig. 4. The switch arm 56 of the double throw switch is operated` bya solenoid 55 which is connected through wires 51 and 53 in seriesthrough an interval timer 60 to a transformer 59 which is connected to a110 v. supply line 33. This same line connects through wires 8| and 62to the timing mechanism of the interval timer 60. This timer is ofstandard design and as is illustrated in the drawings is adjusted toopen the solenoid circuit for 30 seconds and then to close it for thesame period. This interval is very satisfactory for photographicrecording when using a critically damped galvanometer of short period,but any other intervals can be used which are desired.

Wires 54 and 65 lead from the supply line to another interval timer 63which is adjusted to close a switch in the filament circuit of the lamp34 for four minutes and leave it open for one minute. The galvanometeris of standard type critically damped with optical magnification. Thelens 61 (Fig. 4) is of such focal length as to focus perfectly on thedrum 1l! an image of the filament of the source 66. The source 66 may bean incandescent lamp with a single vertical filament which lamp isenclosed in a lighttight housing provided with a vertical slit only wideenough to allow light from the filament to impinge the entire surface ofthe lens 61. The drum is likewise provided with a light-tight housing inwhich is a very fine horizontal slit parallel to the axis of the drumand very close to the drum so that the image of the long lamp filamentis reduced to virtually a point of light when it impinges the drum whichrotates very slowly by means of the constant speed motor 69 and the geartrain 1I, and which drum may be covered with a suitable photographicpaper such as a contrast bromide paper, by which arrangement a spot isrecorded on the photographic paper whenever the galvanometer mirror isstationary for a suiliciently long period of time, say 30 seconds.

Fig. 5 shows a record obtained with the device shown in Figs. l and 4when the reaction mixture in the chamber is a dyebath. It will be notedthat there is a lower line of dots 'l2 which correspond to the readingwhen the galvanometer is switched every 30 seconds onto .phototube 4|.Fluctuations in the level of this line of dots are due to the slightchanges in intensity of radiation of the lamp 34 or other factors in theelectrical system. It is an advantage of the present invention thatwithin reasonable limits such liuctuations do not adversely aiect theaccuracy of e the device. The line of dots 13 corresponds to records ofthe galvanometer during the periods when the interval timer 60 hasswitched the galvanometer onto the phototube 42. It will be noted thatthe start which is portrayed at the left of the record, transmission isvery low at the chosen wavelength, but as the dyeing proceeds the amountof dye remaining in the bath is gradually decreased and the transmissionsteadily increases. In order to establish a base line from which tomeasure the galvanometer deiiection, the lamp 34 is extinguished for 60seconds periodically by the interval timer 63, as described above,during which 60 second interval the dark currents for phototubes 42 and4| are successively recorded, giving rise to the rows of dots 86 and 8l,which correspond to a dark current for the two phototubes by which theactual deflection can be determined by measuring the distance from thesedots to the dots on the other two lines. It will be noticed that theline of dots '|2 is not quite level but shows a gradual rise, probablydue to the discharge of battery 35. Also the lines of dots 86 and 81 arenot level as a result of the drifting of the galvanometer restposition-a common occurrence in sensitive galvanometers. A record inwhich these changes are rather large was purposely chosen in order toillustrate this feature of the invention. Even with a considerablechange, the actual absorption at all times in the cell 6 can beaccurately measured since the discrepancies apparent in dots 13 may beremoved by properly applying the measurements of dots l2, 86 and 8l ascorrections. This is of great importance as the system is not at themercy of fluctuations in light which makes it unnecessary to employextraer dinary means to keep the intensity of the source exactlyconstant, and permits very rugged and simple' colorimeter construction.Furthermore, no error results from galvanometer drift or from changes inelectrical leakage or dark current during an experiment. This is one ofthe advantages of the modication of this invention in that it can beadapted for rough use, for example, in dyeing factories, the cell Sbeing connected to a large dyeing vat. The gures in the drawings show alaboratory type of machine, but of course the invention is not in anyway affected by a change in the shape or size of the reaction chamberand in any dye application this may be a large dye vat or other dyebathcontainer. The size of the container is immaterial so long as arepresentative sample is being continuously circulated through the cell6. In the laboratory device shown in Fig. 1, the circuit is closed, thatis to say, the liquid after passing through the cell 6 is returned byair lift to the reaction vessel. This is necessary in a laboratoryset-up where the reaction vessel is relatively small. In the case oflarge dyebathsy the amount withdrawn to the cell is so small that insome cases it is not worthwhile to recirculate the sample and if desiredthe slight trickle to the cell may be permitted to go to waste. Theoperation of the rest of the device is not of course in any way affectedby this modication.

Fig. 6 shows a slightly different form of laboratory reaction vessel inwhich the cell is oii'set to one side and the mercury U-tube is placedon the other side. This figure also shows an automatic means for fillingthe device without subjecting the liquid to contact with the air. Thisis effected by using the gas which is employed for circulation in theair lift to pump in liquid to fill the reaction chamber. The gas isshown as coming from a suitable pressure tank or pump through the fpipe2| and a couple of wash bottles 22 up through the pipe 23 into a gas imoistening chamber 83 and thence to the air lift through pipe 24. Pipe26 leads to the reservoir 30. Liquid from the reservoir rises in thetube 29 and the height of the liquid column serves to measure thepressure under which the gas is flowing into the air lift. The reservoirmay be l lled through 93. Liquid may be transferred from the reservoirto the reaction vessel by opening stop cock 25 and pressure within thesystem may be released by opening stop cock 3|. Change in dilution ofthe reaction solution is prevented by pum-ping the gas used in the liftthrough a body of the same liquid used in the reaction chamber (usuallywater) in the vessel 83. Pumping of the gas results from the fact thatIpipe 2| connects to a pressure tank in which the gas used is maintainedat a sufficient pressure toproduce the desired flow. As a result the gasused in the air lift is saturated with moisture at the elevatedtemperature and no loss from the Y reaction chamber will take place. Theoperation of the modied reaction chamber and circulating system shown inFig. 6 is otherwise exactly the same as that in Fig. l.

This application is a division of our copending application Serial No.354,702, filed August 29, 1940.

We claim:

1. A device for measuring changes of absonption of optical radiation ina reaction which comprises in combination a transparent cell, means forcontinuously circulating a small portion of liquid through said cell, asource of light, means for producing two beams from said source oflight, radiation detecting means in each of said beams capable oftransforming radiant energy received into electric energy, means forcausing radiant energy of predetermined frequency range only to strikethe two detecting means, the frequency range being the same for eachbeam, said transparent cell being located in one of said beams, arecording galvanometer and means for alternating recording by thegalvanometer current from the radiation detecting means from each beam.

2. A device for measuring changes of absorption of optical radiation ina reaction which comprises in combination a transparent cell, means forcirculating liquid through said cell, a source of light, a plurality oflenses producing two beams from said source of light, said cell being inoptical alignment with one of said beams, means for causing each beam toconsist of the same predetermined frequency range of radiation,radiation detecting means for each oi' said beams capable oftransforming radiant energy received into electrical energy, a recordinggalvanometer, means forA alternately recording by the galvanometer thecurrent from the radiation detecting means in each beam and means forperiodically extinguishing the beams through a cycle in which the darkcurrent of each radiation detecting means will be recorded.

3. A device according to claim 2 in which the galvanometer is of themirror type reflecting a beam of light and said beam of light is causedto impinge on a slowly moving surface capable of photographicallyrecording the reflected beam from the galvanometer as a series ofdots.

ROY HERMAN KIENLE. ROBERT H. PARK. CHARLES H. BENBROOK. EVERETI F.GRIEB.

